The study intends to determine the optimal time to start ART by comparing three treatment strategies of ART initiation in HIV/TB co-infected patients. Four hundred fifty newly diagnosed HIV infected patients with active TB and CD4 cell count < 200 cells/mm3 will be prospectively recruited to be assigned randomly in parallel into one of the three treatment groups (n=150 in each group) and HAART will be started at different time points as described below with extensive counseling and adherence support.